This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is a case-control observational study that directly monitors the growth of uterine leiomyomas in 320 women using oral contraceptives by using serial ultrasound evaluations. All subjects will have serum and urine assays to establish if Black women produce higher levels of sex steroids than their White counter-parts. An objective will be to determine if OC accelerates the development of new leiomyomas in women with existing leiomyomas. Subjects will be recruited at Meharry Medical College and Penn State facilities. The study will involve 9 visits, once monthly for months 1-3 and then every 6 months for 3 years. The target population is reproductive aged women with leiomyomas who have a minimum of factors that could potentially affect leiomyoma growth. Because leiomyomas disporportiontely affect Black women, it is anticipated that this study would primarily enroll minority subjects and the enrollment ratio of Black to White women will be 2:1. There are plans to enroll 320 subjects.